package com.hirsi.common.core.util;

import cn.hutool.core.util.StrUtil;
import cn.hutool.http.useragent.UserAgent;
import com.hirsi.common.core.constant.HeaderConstant;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

public class HttpContextUtil {

    public static HttpServletRequest getRequest() {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        return attributes != null ? attributes.getRequest() : null;
    }

    public static HttpServletResponse getResponse() {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        return attributes != null ? attributes.getResponse() : null;
    }

    public static String getUrl() {
        HttpServletRequest request = getRequest();
        if (request == null) return null;
        return request.getRequestURI();
    }

    public static String getUserAgent() {
        HttpServletRequest request = getRequest();
        if (request == null) return null;
        return request.getHeader(HeaderConstant.USER_AGENT);
    }

    public static Map<String, String[]> getParam() {
        HttpServletRequest request = getRequest();
        if (request == null) return new HashMap<>();
        return request.getParameterMap();
    }

    public static String getMethod() {
        HttpServletRequest request = getRequest();
        if (request == null) return null;
        return request.getMethod();
    }

    /**
     * 获取IP地址
     * <p>
     * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    private static final String UNKNOWN = "unknown";
    private static final String LOCALHOST_IP = "0:0:0:0:0:0:0:1";
    private static final String LOCALHOST_IP1 = "127.0.0.1";
    private static final String IP_UTILS_FLAG = ",";
    public static String getIpAddr() {
        String ip = null;
        HttpServletRequest request = getRequest();
        try {
            //以下两个获取在k8s中，将真实的客户端IP，放到了x-Original-Forwarded-For。而将WAF的回源地址放到了 x-Forwarded-For了。
            ip = request.getHeader("X-Original-Forwarded-For");
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("X-Forwarded-For");
            }
            //获取nginx等代理的ip
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("x-forwarded-for");
            }
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            //兼容k8s集群获取ip
            if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (LOCALHOST_IP1.equalsIgnoreCase(ip) || LOCALHOST_IP.equalsIgnoreCase(ip)) {
                    //根据网卡取本机配置的IP
                    InetAddress iNet = null;
                    try {
                        iNet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        //log.error("getClientIp error: {}", e);
                    }
                    ip = iNet.getHostAddress();
                }
            }
        } catch (Exception e) {
            //log.error("", e);
        }
        //使用代理，则获取第一个IP地址
        if (!StrUtil.isEmpty(ip) && ip.indexOf(IP_UTILS_FLAG) > 0) {
            ip = ip.substring(0, ip.indexOf(IP_UTILS_FLAG));
        }
        return ip;
    }
}
